Forests and their catchments are dynamic and complex natural systems that demand detailed study of local climate change trends and impacts on water resources. In order to understand their ecological complexity and dynamism it is necessary to study the precipitation, temperature, evaporation and runoff at multiple spatial and temporal scales. Based on daily meteorological data from Xiagongtang station in 1975-2015 and runoff from Number 4 station from 2009-2013 in Jiulianshan, climate and stream flow characteristics and their relationships were analyzed using accumulative anomaly and wavelet transformation. We found that the mean annual temperature was 17.1℃, mean annual precipitation was 1816.3 mm and mean annual evaporation was 781.6 mm. The precipitation from March to October was 82.6% of annual precipitation. The mean annual temperature presented an increasing trend with a trend rate of 0.14℃/10 a for past years whereas precipitation and evaporation declined with a slope of -11.81 mm/10 a and -50.13 mm/10 a, respectively. At the same time, there were significant main periods of quasi 14 years for temperature, precipitation and evaporation, and a minor cycle of quasi 20 years for precipitation. The surface runoff was 1066.2 mm and runoff coefficient was 0.54. There was a significantly positive correlation between precipitation and surface runoff. After heavy rainfall discharge returning to the original level before raining might take about 12-48 h. In a year, there were significant periods at a scale of 20 and 60 days for surface runoff, precipitation and evaporation and the response of runoff variation to climate change was significant. Precipitation had a significant impact on surface runoff as well as evaporation. These results showed that forests and climate change have an important role modifying cycles of runoff and precipitation in subtropical mountain catchments.